Starlink satellites were launched in a large stack on a Falcon 9 rocket. Photo: SpaceX/Forbes says that three of its 60 controversial Starlink satellites have failed in orbit, as the company moves towards the first broadcasting test of its ambitious space internet constellation.

In a statement, the U.S.-based company revealed that 57 of its Starlink satellites were successfully communicating with stations back on Earth. Of these, 45 had reached their desired altitude of 550 kilometers with their onboard propulsion systems, five were still raising their altitude from initial orbits of 440 kilometers, and a further five were going through tests before doing so.